scsi: mpt3sas: Use configured PCIe link speed, not max

When enabling high iops queues, the driver should use the HBA's configured
PCIe link speed instead of looking for the maximum link speed.

I.e. enable high iops queues only if Aero/Sea HBA's configured PCIe link
speed is set to 16GT/s.

Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>